The present invention pertains to vacuum valves for applied processing systems and, more particularly, to an improved quick release clamp mechanism for connecting and disconnecting the bonnet and flange of gate valves.
My U.S. Pat. No. 5,791,632, entitled xe2x80x9cQuick Release Slide Lock for Vacuum Valve,xe2x80x9d discloses a quick release clamp mechanism for releasing or disengaging the bonnet of the gate valve actuator from the valve body flange associated therewith. The disclosure of this reference is incorporated herein. While the quick release mechanism disclosed in this patent provides an efficient quick release and a tight seal for operation, the drive of the computer chip manufacturing industry to smaller and smaller processing systems makes servicing and performing routine maintenance of such systems more difficult. The present invention addresses these difficulties with an improved quick release mechanism that better takes advantage of limited, yet available, space.
Briefly described, the improved vacuum valve of the present invention comprises a clamp actuator that extends through the end plate of a valve housing that defines a valve chamber and includes a main opening. The clamp actuator extends from above the end plate and is connected to a clamp mechanism of the valve for moving the clamp mechanism between its first position and its second position. A valve plate is provided that is movable within the valve chamber from a first, open position away from the main opening to a second, closed position wherein the valve plate closes the main opening to prevent vacuum media flow, and a valve plate actuator moves the valve plate between its open and closed positions. The valve plate actuator and valve plate are secured to the end plate so that removal of the end plate in an upward direction separates the valve plate actuator and valve plate from the actuator end of the valve housing. The valve housing also includes an end plate engaging member. Further, the clamp mechanism is coupled to one of the end plate and end plate engaging member, with the clamp mechanism having a first position allowing separation of the end plate from the end plate engaging member and a second position that securely holds the end plate to the end plate engaging member in a sealed manner.
In this manner, access is provided from the actuator end of the vacuum valve, or at least from the outer side of the valve actuator, which allows for more compact design of the vacuum valve, while at the same time providing easy access for repair and maintenance purposes.
According to an aspect of the invention, the clamp actuator includes a pinion component and the clamp mechanism includes a rack component coupled to the pinion component, whereby rotation of the pinion component causes linear movement of the rack component, causing the clamp mechanism to move between its first and second positions. Preferably, the clamp actuator includes an elongated drive shaft connected to the pinion component, the elongated drive shaft extending away from the end plate beyond an outer end of the valve plate actuator, to provide access from above the end plate for service.
According to another aspect of the invention, the drive shaft includes an outer end that has a drive coupling for manual rotation of the drive shaft and connected pinion component, in order to shift the clamp mechanism.
These and other features, advantages and objects of the invention will become apparent from the following description of the best mode for carrying out the invention, when read in conjunction with the accompanying drawings, and the claims, which are all incorporated herein as part of the disclosure of the invention.